Nontoxic and Non-incendiary Obscurant Compositions and Method of Using Same

ABSTRACT

White smoke formulations comprising triazine-borate cage compounds or triazine-phosphate cage compounds obscurants and a sucrose-potassium chlorate pyrotechnic fuel-oxidizer system are disclosed.

FIELD OF THE INVENTION

This invention relates to a composition that produces a non-toxic,non-incendiary, and highly obscuring cloud of smoke upon combustion anda method of making obscurant devices based on said composition.

BACKGROUND OF THE INVENTION

A burgeoning need exists for efficient, nontoxic highly obscuring smoke,which is produced at relatively low combustion temperatures. Currentconventional smoke formulations, for examples, hexachloroethane (HC)smokes and red phosphorus (RP) smokes, have high burn temperatures,which pose a dangerous and undesirable secondary fire risk to structuresand personnel especially within high density urban warfare environments.

SUMMARY OF THE INVENTION

Certain embodiments of Applicant's disclosure disclose white smokeformulations comprising triazine-borate cage compounds ortriazine-phosphate cage compounds obscurants and a sucrose-potassiumchlorate pyrotechnic fuel-oxidizer system.

Applicant's white smoke formulations exhibit low peak combustiontemperatures, high visual obstruction properties, and gradient burncharacteristics.

Further, when a burn rate modifier, either a burn rate accelerant or aburn rate retarder, is added to the white smoke formulations, adifference greater than 40% in burn rate is observed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood from a reading of the followingdetailed description taken in conjunction with the drawings in whichlike reference designators are used to designate like elements, and inwhich:

FIG. 1 illustrates transmittance percentages of RP smoke and themelamine/acetoguanamine triazine borate (MATEAB) white smokeformulation;

FIG. 2 illustrates different embodiments of smoking devices withgradient burn characteristics;

FIG. 3A shows mass extinction coefficient values of the METEAB whitesmoke formulation with Chlorez polychlorinated wax latent HCL additiveis tested under about 80% ambient humidity;

FIG. 3B illustrates the mass extinction coefficient values of the MATEABwhite smoke formulation with sucralose latent HCl additive is testedunder about 80% ambient humidity;

FIG. 3C shows the mass extinction coefficient values of the MATEAB whitesmoke formulation with PEPA latent phosphoric acid additive is testedunder about 20% ambient humidity;

FIG. 3D illustrates the mass extinction coefficient values of the MATEABwhite smoke formulation with PEPA latent phosphoric acid additive istested under about 80% ambient humidity;

FIG. 4 shows that the MATEAB white smoke formulation has a higher massextinction coefficient value a (m²/g) at visible light spectralwavelengths most sensitive to the photopic cone (550 nm) and scotopicrod cells (500 nm) responsible for human eye vision compared to TA andRP smoke formulations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention is described in preferred embodiments in the followingdescription with reference to the Figures, in which like numbersrepresent the same or similar elements. Reference throughout thisspecification to “one embodiment,” “an embodiment,” or similar languagemeans that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least one embodimentof the present invention. Thus, appearances of the phrases “in oneembodiment,” “in an embodiment,” and similar language throughout thisspecification may, but do not necessarily, all refer to the sameembodiment.

The described features, structures, or characteristics of the inventionmay be combined in any suitable manner in one or more embodiments. Inthe following description, numerous specific details are recited toprovide a thorough understanding of embodiments of the invention. Oneskilled in the relevant art will recognize, however, that the inventionmay be practiced without one or more of the specific details, or withother methods, components, materials, and so forth. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of the invention.

Applicant's disclosure addresses these issues by developing formulationsthat produce low toxicity and highly visually obscuring white smoke atlow combustion temperature (Peak Exotherm Temperature <400° C.). Theseformulations also exhibit a gradient burn rate characteristic, whichinitially rapidly release smoke accompanied by gradual slowing of smokeproduction rate. This characteristic enables both rapid dispersal andmaintenance of a higher density smoke screen that can be achieved viaconventional and more linear burn rate smoke munitions.

Applicant's disclosure benefits in terms of both enhanced militarycapability coupled with cost reduction. Such benefits are described ingreater details below.

In certain embodiments, given the smoke formulations' low peakcombustion temperature coupled with gradient burn characteristics, thesmoke formulations offer enhanced military capabilities particularly inhigh density urban conflict environments where secondary fire risktowards personnel and structures is of concern. Gradient burn ratecharacteristics are advantageous since this enables rapid, initial smokescreen establishment accompanied by its maintenance and persistence fortime durations longer than conventional smoke munitions. Persistentsmoke screens are desirable because they offer greater and longerprotection towards personnel and hardware.

The Applicant's smoke formulations are compatible with the current smokemanufacturing paradigm and are formulated from inexpensive, readilycommercially available components which do not have restrictivetransportation and handling and storage requirements associated with HC,RP, or white phosphorus (WP) smokes. The instant smoke compositions notonly demonstrate low-toxicity and enhanced obscuration properties, butalso are more cost effective than other existing candidates. A series ofhighly obscuring pyrotechnic smoke formulations comprisingtriazine-borate or phosphate cage compound obscurants blended withconventional sucrose-potassium chlorate pyrotechnic propellant have beendeveloped. Triazines comprise six membered carbon-nitrogen heterocycliccompounds including melamine, acetoguanamine, benzoguanamine and theirN-acylated (i.e. N-Acetyl Melamines, N-Trihalooacetyl Melamines),N-Arylated and/or N-Alkylated derivatives. In other embodiments, thetriazines can be in partial or completely neutralized salt form. In yetother embodiments, the triazines can be as free base. In certainembodiments borate and phosphate cage compounds comprise trialkanolaminederived borate or phosphate compounds including but not limited totriethanolamine borate, triisopropanolamine borate, pentaerythritolborate (free acid or its ammonium, alkyl ammonium, aryl ammonium,pyridinium, anilinium, triazinium, or guanidinium salts) triethanolaminephosphate, pentaerythritol phosphate alcohol (PEPA) and PEPA carboxylateor silicate esters.

In certain embodiments, Applicant's smoke formulations not only containnew obscurant chemicals, but also that their combustion characteristics,such as, burn rate or peak exotherm combustion temperature, can becustomized and controlled by adding minor amounts of burn rate modifiers(accelerants or retardants).

Applicant has developed smoke formulations suitable for 155 mm smokecanister munitions having lower peak combustion temperatures (T<400°C.), higher obscuration properties (>200%), relative to conventional TAsmoke, and gradient burn rate characteristics (customizable longer anddenser smoke production) relative to corresponding conventional nontoxicand non-incendiary 37 mm smoke canister, AN-M8 smoke grenade, AN-M83smoke grenade, and/or 155 mm (e.g. short M116A1 or long M825A1) smokemunitions. “About” described herein is used to capture any internalmeasure errors.

Further, Applicant has found that small amounts (<5 wgt. %) of burn ratemodifiers can be separately and successfully formulated into Applicant'swhite smoke composition. In certain embodiments, an accelerant isselected from the group consisting of manganese dioxide (MnO₂), cobaltoxide (Co₃O₄), iron oxide (Fe₂O₃), manganese chloride tetrahydrate(MnCl₂-4H₂O), cobalt chloride hexahydrate (CoCl₂-6H₂O), iron chloridehexahydrate (FeCl₃-6H2O), and any combinations thereof. In otherembodiments, an accelerant comprise a high surface area heterogeneouscombustion catalyst, such as high surface area carbon, metal, metalcarbide, metal oxide and the like. Further, a retarder is selected fromthe group consisting of oxamide, biuret, nitroguanidine, urea, calciumcarbonate, calcium sulphate, ammonium chloride, ammonium sulphate,dicyanoguanidine, chlorinated hydrocarbons, aluminum hydroxide, ammoniumsalts (sulphate, oxalate, phosphate), lithium fluoride, strontiumcarbonate, N-bromosuccinimide, hexabromocyclododecane,pentabromodiphenyl oxide, decabromodiphenyl oxide,tetrabromophthalatediol, tetrabromophthalic anhydride, triphenylantimony, diammonium bitetrazole, 5-aminotetrazole, ammoniumpolyphosphate, and any combinations thereof.

Applicant has found that the modified MATEAB white smoke formulations,i.e., small amount of burn rate modifiers are added to saidformulations, exhibit >±20% burn rate difference between unmodifiedMATEAB control white smoke, i.e., small amount of burn rate modifiersare not added to said formulations.

Moreover, Applicant has found that pellets can be pressed with modifiedMATEAB white smoke formulations and that the modified MATEAB white smokeformulation pellets exhibit low peak combustion temperatures (T<400° C.)and higher obscuration properties (>200%) relative to conventionalnontoxic and non-incendiary smoke. Furthermore, the modified MATEABwhite smoke formulation pellets can be loaded into subscale devices,such as 37 mm, M8, M83 grenades, 155 mm smoke projectiles, etc.

In addition, gradient burning characteristics are imparted torepresentative above listed devices by varying burn rate modifiedpellets either axially (end burning pellet configuration) or radially(core burning pellet configuration). Adding minor amounts of burn rateaccelerants or retardants enable more efficient and prolonged smokescreen generation than smoke screen generation achieved throughconventional smoke devices. The representative above devices chargedwith modified MATEAB white smoke formulations have low peak combustiontemperatures (T<400° C.) and higher obscuration properties (>200%)relative to conventional nontoxic and non-incendiary smoke. Further, themodified MATEAB white smoke formulations can be successfully scaled upinto a bulk production, i.e., approximately >10 Kg/day process.

In certain embodiments, Applicant's smoke devices are prepared to havesmoke charges containing desired burn rate modifier compositiongradients which vary either radially (gradient core burningconfiguration) or axially (gradient end burning configuration).Referring to FIG.2, a smoking device 200 comprises a pyrotechnic charge202, which is disposed throughout all pyrotechnic pellets 204 a-e. In adifferent embodiment of a smoking device 300, the pyrotechnic charge 302has a reversed conical shape. Both smoking device 200 and smoking device300 are non-limiting examples of gradient core burning configuration. Inother embodiments, each pellet can have a different size of apyrotechnic charge. The different surface area contacting a pyrotechniccharge within a pyrotechnic pellet contributes to a different burn ratethereof.

Inclusion of a burn rate retarder or accelerant introduces a compositiongradient into the charge and thereby effecting charge combustion and theamount of smoke produced at various time intervals by a device. Incertain embodiments, each pyrotechnic pellet comprises either aretardant or an accelerant. Pyrotechnic pellets 204 a-e can all have thesame weight percentage of a retardant or an accelerant. In otherembodiments, pyrotechnic pellets 204 a-e can each has a different weightpercentage of a retardant or an accelerant, therefore, the smokingdevice 200 comprises a composition gradient which effect the combustionfront burn rate and amount of smoke emitted at various pre-determinedlocations along the pyrotechnic charge 202. Similarly, the pyrotechnicpellets 304 a-e can each has a different weight percentage of aretardant or an accelerant, therefore, the smoking device 300 comprisesa composition gradient which effects the combustion front burn rate andamount of smoke emitted at various pre-determined locations along thepyrotechnic charge 302.

In certain embodiments, a smoking device 400 illustrates a non-limitingexample of gradient end burning configuration. The smoke device 400comprises a pyrotechnic charger 402, a plurality of pyrotechnic pellets404 a-e, and an exit orifice 406. In certain embodiments, Burn retardantconcentration within fast, initial end burning devices would varydirectly with distance to device orifice whereas slow initial endburning devices would possess higher retardant concentrations withinclose proximity to the device orifice. In some embodiments, a burn rateretardant comprises a chemical compound which inhibits pyrotechniccharge burn rate (e.g. oxamide, biuret or related derivatives). In otherembodiments, a burn rate retardant comprises an inert filler whichmerely decreases active pyrotechnic charge areal concentration.

In certain embodiments, one could also produce a fast end burning devicevia introducing high concentrations of burn rate accelerant in thepyrotechnic pellets at close distances to the exit orifice accompaniedby a tapering off and/or inclusion of retardant at distances furtheraway from the exit orifice.

The following examples are presented to further illustrate to personsskilled in the art how to make and use the invention. These examples arenot intended to be limiting.

EXAMPLE 1 Synthesis of OCC Obscurants

In certain embodiments, OCC obscurants are synthesized because unliketheir parent acids, OCC compounds have cyclic structures allowing readysublimation at low temperatures as evidenced by their reasonably lowheat of vaporization thermodynamic properties. OCC compounds comprisingnon-toxic pentaerythritol phosphate alcohol (PEPA) 3, esterifiedderivatives thereof, triethanolamine borate (TEAB) 6, are formedaccording to the following equations:

In certain embodiments, OCC compounds comprises pentaerythritol borate8, having a structure of

and/or triethanolamine phosphate (TEAP) 7, having a structure of

TEAB 6 can be efficiently sublimed at low temperatures (T<250° C.) usingconventional sucrose-chlorate pyrotechnic composition. Upon combinationwith atmospheric moisture, TEAB 6, PEPA 3, pentaerythritol borate, andTEAP 7 decompose to nontoxic highly obscuring hydrated polyboric orpolyphosphoric acid aerosol smoke particles. In certain embodiments,these acids readily form stable, strongly hydrogen bonded salt aerosolsmoke particles with co-sublimed alkaline melamine and acetoguanamineobscurants. Further, MATEAB white smoke aerosol particles are efficientat scattering visible light. Further, the triazine borates andphosphates show low acute toxicity.

A variety of synthetic strategies and precursor compounds are evaluatedincluding via direct esterification and transesterification routes todetermine the optimal means for efficient TEAB 6 and TEAP 7 production.

Table 1 summarizes the properties of several obscurant compounds.

TABLE 1 Total Number of Hydrogen Density ΔH_(vap) Bonding CompoundStructure δ (cal^(1/2)ml^(−1/2))^(a) (g/mL)^(b) (cal/g) Sites^(b)Terephthalic Acid (TA)

12.0 1.51 99 6 Melamine

16.0 1.66 155 12 Acetoguanamine

13.7 1.39 135 9 Triethanolamine Borate (TEAB)

8.15 1.13 58.8 4 Pentaerythritol Phosphate Alcohol (PEPA)

10.3 1.35 78.4 6 ^(a)δ values calculated from Van Krevelen, D. W.Properties of Polymers, 3^(rd) ed.; Elsevier: New York, 1997.⁴^(b)Density values and H-bonding sites calculated using ACD/LabsSoftware V 11.01 on CAS SciFinder Scholar.

EXAMPLE 2

Mixtures between TEAB 6 and similar structured PEPA 3 cage compoundobscurants within conventional sucrose-chlorate pyrotechnic propellantare prepared and evaluated (see Tables I & II below for representativeMATEAB white smoke and MATEAB-PEPA white smoke producing pyrotechnicformulations.) Blending was accomplished within acetone vehicle followedby mixing via a Kitchen Aid Planetary Mixer. The resultant powder blendwas subsequently dried within an air convection oven at 40° C. followedby compaction into candidate one inch diameter pyrotechnic pellets via aCaver Hydraulic Press operating at 5000 lb dead load for 10 secondduration. An acetone slurry of 511 igniter composition was applied anddried atop of each pellet followed by ignition using a nichromeresistance wire heater (see Table V below for 511 igniter compositionemployed).

TABLE II MATEAB Pyrotechnic White Smoke Formulation (1) Component Weight% Potassium Chlorate Oxidizer 33.75 Sucrose Fuel 13.31 MelamineObscurant 21.86 TEAB Obscurant 16.75 Acetoguanamine Obscurant 14.33

TABLE III MATEAB Pyrotechnic White Smoke Formulation (2) ComponentAmount (g) Weight % Potassium Chlorate Oxidizer 33.75 33.70% SucroseFuel 13.40 13.38% Melamine Obscurant 21.87 21.84% TEAB Obscurant 16.7816.75% Acetoguanamine Obscurant 14.36 14.34%

TABLE IV MATAEB - PEPA Pyrotechnic White Smoke Formulation ConcentrationComponent (Weight %) Potassium Chlorate 32.14 Sucrose 12.68 Melamine20.82 TEAB 15.95 Acetoguanamine 13.64 PEPA 4.77

TABLE V 511 Igniter Composition Employed to Ignite MATEAB & MATEAB PEPAPyrotechnic White Smoke Producing Formulations Concentration Component(Weight %) Silicon Metal (325 Mesh) 26.0 Potassium Nitrate 35.0 Iron(II) Oxide, Black 22.0 German Blackhead Aluminum Powder 13.0 CharcoalPowder 4.0

In certain embodiments, other latent HCL source, other than sucrose, canbe used in MATEAB and/or MATEAB PEPA Pyrotechnic White Smoke Producingformulations. The latent HCl source comprises sucralose having astructure of

and/or Chlorez chlorinated wax having a structure of

Referring to FIG. 3A, the mass extinction coefficient values of theMATEAB white smoke formulation with Chlorez wax latent HCl additive istested under about 80% ambient humidity.

Referring to FIG. 3B, the mass extinction coefficient values of theMATEAB white smoke formulation with sucralose latent HCl additive istested under about 80% ambient humidity.

Referring to FIG. 3C, the mass extinction coefficient values of theMATEAB white smoke formulation with PEPA latent phosphoric acid additiveis tested under about 20% ambient humidity.

Referring to FIG. 3D, the mass extinction coefficient values of theMATEAB white smoke formulation with PEPA latent phosphoric acid additiveis tested under about 80% ambient humidity.

Table VI summarizes the mass extinction coefficient values of the MATEABwhite smoke formulation, the MATEAB white smoke formulation with Chlorezwax latent HCl additive, the MATEAB white smoke formulation withsucralose latent HCl additive, and the MATEAB white smoke formulationwith PEPA latent phosphoric acid additive.

EC400 EC500 EC600 Relative Formulation (M{circumflex over ( )}2/g)(M{circumflex over ( )}2/g) (M{circumflex over ( )}2/g) Humidity MATEAB0.58 1.74 1.87 20% MATEAB 1.64 1.1 2.33 80% MATEAB + 2.5 0.89 1.7 1.9320% mol % sucralose replacement MATEAB + 2.5 0.80 1.86 2.18 80% mol %sucralose replacement MATEAB + 5 0.97 1.7 1.57 20% mol % sucralosereplacement MATEAB + 5 0.42 0.56 2.14 80% mol % sucralose replacementMATEAB + 10 0.37 2.4 1.44 20% mol % sucralose replacement MATEAB + 100.37 0.88 1.81 80% mol % sucralose replacement MATEAB + 3% 0.35 1.010.78 20 by wt Chlorez + 0.5% by wt nitrocellulose + 1% by wt SMA EF60MATEAB + 3% 0.10 1.62 1.90 80 by wt Chlorez + 0.5% by wtnitrocellulose + 1% by wt SMA EF60

In certain embodiments, the obscurants are finely ground and Roto-Tapscreened followed by blending with measured amounts of confectionarygrade sucrose sugar fuel and potassium chlorate oxidizer. Variousamounts of obscurant and sucrose-chlorate propellant are mixed withinacetone solvent using an overhead Hobart Mixer followed by carefuldrying. The resulting dried obscurant and propellant powder mixtures areseparately reground, Roto-Tap screened, and pressed into candidate smoketesting pellets using a hydraulic Carver Press within a cylindricalsteel mold (about 6,000 lbs compaction load/15 second load duration).

Representative pellets are then separately combusted and the resultingsmoke obscuring properties are characterized as a function ofincandescent interrogation light wavelength at various ambient humiditylevels using a smoke box outfitted with a Thorlabs CCS200 Compact FiberVisible/Near Infrared (NIR) Spectrometer (500-1000 nm spectral sensingwavelength range, with 4 nm resolution). A mixing fan is incorporatedinto the smokebox to ensure the smoke is uniformly homogenized withinthe 0.112 m³ chamber volume. Pellet ignition is accomplished using anelectrically resistive Nichrome wire igniter situated atop the pelletsurface. An incandescent lamp, which is used to interrogate the pelletcombustion smoke, is set to 6 Volts and the path length to a.Comparative testing is conducted in smoke box for OCC versusconventional sized TA pellet formulations.

In certain embodiments, the pellet combustion trials within the smokebox entails smoke formulations comprising compounds mixtures betweentriazines and TEAB 6 or triazines and TEAP 7. The baseline obscuringproperties of the MATEAB smoke formulations without burn rate modifiersare established first. Then pellets comprising MATEAB smoke formulationsare reformulated with burn rate modifiers and modified obscuringproperties are evaluated.

Table VII and Table VIII summarize the properties of several chlorateoxidizers and metal oxides.

TABLE VII (Smoke Formulation Pyrotechnic Propellant DecompositionCatalysts & Reported Chlorate Oxidizer Half Mass DecompositionTemperatures) 50% Chlorate Metal Cation d Decomposition Shell ElectronicMelting Point Temperature Catalyst Configuration ¹ (° C.) (° C.) ¹CoCl₂—6H₂O d⁷ 86 317 FeCl₃ 6H₂O d⁵ 37 340 MnCl₂—4 H₂O d⁵ 58 400

TABLE VIII (Melting Point of Corresponding Proposed Smoke FormulationPyrotechnic Propellant Decomposition Catalyst Metal Oxides) Metal Cationd Shell Electronic Melting Point Metal Oxide Configuration ¹ (° C.)Co₃O₄, d⁶ 895 Fe₂O₃ d⁵ 1539 MnO₂, d² 535

EXAMPLE 3

In the embodiment illustrated by FIG. 1, line 100 and line 110 show thetransmittance percentages of the RP smoke formulation and the testedMATEAB white smoke formulation, which is defined by the y-axis 120,during a time period, which is defined by the x-axis 130. As indicatedby FIG. 1, the transmittance percentage of the RP smoke formulation issignificantly higher than the transmittance percentage of the testedMATEAB white smoke formulation during a period of about 10 minutes.“About” as described herein is used to capture internal measure errors.

Table IX lists the components of the said MATEAB white smokeformulation.

TABLE IX (MATEAB White Smoke Formulation) Concentration ComponentFunction (wgt. %) Potassium Chlorate Oxidizer 33.46 Sucrose Fuel 13.2Melamine Obscurant Component 21.68 Triethanolamine Borate ObscurantComponent 16.61 Acetoguanamine Obscurant Component 14.21 NitrocellulosePellet Binder 0.83

In certain embodiments, the MATEAB white smoke formulation (Table 4)when tested in an aerosol chamber exhibits higher obscuring performancerelative to conventional terephthalic acid (TA) and red phosphorus RPsmoke formulations.

Referring to FIG. 4, the MATEAB white smoke formulation has a highermass extinction coefficient value a (m²/g) at visible light spectralwavelengths most sensitive to the photopic cone (λ≈550 nm) and scotopicrod cells (λ≈500 nm) responsible for human eye vision compared to TA andRP smoke formulations. In chemistry, biochemistry, molecular biology, ormicrobiology, the mass extinction coefficient and the molar extinctioncoefficient (also called molar absorptivity) are parameters defining howstrongly a substance absorbs light at a given wavelength, per massdensity or per molar concentration, respectively. The mass attenuationcoefficient or mass narrow beam attenuation coefficient of the volume ofa material characterizes how easily it can be penetrated by a beam oflight, sound, particles, or other energy or matter. In addition tovisible light, mass attenuation coefficients can be defined for otherelectromagnetic radiation (such as X-rays), sound, or any other beamthat attenuates. The SI unit of mass attenuation coefficient is thesquare metre per kilogram (m²/kg). Further, the MATEAB white smokeformulations are shelf-stable and maintained their obscuring performanceand significant extinction coefficients even after continuous isothermalaging of smoke pellet formulations for longer than 8 weeks.

Table X summarizes the mass extinction coefficient values of the MATEABwhite smoke formulation, TA smoke, and RP smoke.

TABLE X (Mass Extinction Coefficients for Various Smoke Formulation) α @550 nm α @ 500 nm Smoke Formulation (m²/g) (m²/g) MATEAB 5.11 5.25 TA4.85 4.71 RP 4.0 4.35

Table XI summarizes the mass extinction coefficient values (m²/kg) ofthe MATEAB white smoke formulation and TA/PE smoke.

Formulation 500 nm 550 nm 950 nm MATEAB 1.72 ± 0.25 1.90 ± 0.25 0.92 ±0.10 TA/PE 0.54 ± 0.12 0.49 ± 0.12 0.20 ± .06 

While the preferred embodiments of the present invention have beenillustrated in detail, it should be apparent that modifications andadaptations to those embodiments may occur to one skilled in the artwithout departing from the scope of the present invention.

We claim:
 1. A composition to produce smoke upon combustion, comprisinga triazine, wherein said triazine has obscurant characteristics.
 2. Thecomposition of claim 1, wherein further comprising a second obscurant.3. The composition of claim 1, wherein said triazine is selected from agroup consisting of melamine, N-acylated melamine, N-arylated melamine,N-alkylated melamine, acetoguanamine, N-acylated acetoguanamine,N-arylated acetoguanamine, N-alkylated acetoguanamine, benzoguanamine,N-acylated benzoguanamine, N-arylated benzoguanamine, N-alkylatedbenzoguanamine, and any combinations thereof.
 4. The composition ofclaim 2, wherein said second obscurant is selected from a groupconsisting of triethanolamine borate, triethanolamine phosphate,pentaerythritol borate, pentaerythritol phosphate alcohol,pentaerythritol phosphate alcohol carboxylate, silicate esters, and anycombinations thereof.
 5. The composition of claim 4, wherein said secondobscurant is triethanolamine borate.
 6. The composition of claim 1,further comprising a propellant, wherein the propellant comprises anoxidizer and a fuel.
 7. The composition of claim 6, wherein saidoxidizer is selected from a group consisting of alkali, alkaline earthchlorate, potassium chlorate, sodium chlorate, and any combinationsthereof.
 8. The composition of claim 7, wherein said oxidizer ispotassium chlorate.
 9. The composition of claim 6, wherein said fuel isone or more carbohydrates.
 10. The composition of claim 9, wherein saidfuel is sucrose.
 11. The composition of claim 1, wherein said smokeproduced by combustion of the composition has a low peak combustiontemperature.
 12. The composition of claim 11, wherein said low peakcombustion temperature is lower than 350° C.
 13. The composition ofclaim 1, wherein said smoke produced by combustion of the compositionhas a high obstruction property, wherein said high obscuration propertyis greater than 200% transmittance.
 14. The composition of claim 1,wherein said smoke produced by combustion of the composition has agradient burn rate characteristic, wherein the produced smoke lastslonger and denser.
 15. The composition of claim 1, wherein furthercomprising a burn rate retarder.
 16. The composition of claim 15,wherein said burn rate retarder is selected from the group consisting ofoxamide, biuret, and derivatives thereof.
 17. The composition of claim16, where said burn rate retarder causes over about 40% reduction inburn rate.
 18. The composition of claim 1, wherein further comprising aburn rate accelerant.
 19. The composition of claim 18, wherein said burnrate accelerant is selected from the group consisting of manganesedioxide (MnO₂), cobalt oxide (Co₃O₄), iron oxide (Fe₂O₃), manganesechloride tetrahydrate (MnCl₂-4H₂O), cobalt chloride hexahydrate(CoCl₂-6H₂O), and iron chloride hexahydrate (FeCl₃-6H2O).
 20. Thecomposition of claim 19, wherein said burn rate accelerant is MnO₂ andcauses over about 20% increase in burn rate.